Intravenous tubing clamping device

ABSTRACT

An intravenous tubing clamping device is provided for controlling fluid flow through compressible tubing. The device includes an elongated member having a proximal end and a distal end which is adapted to receive the tubing. The body member has a generally V-shaped longitudinally extending bottom wall having an angle of about 60° to 165° defining two supporting surfaces for the tubing. In one embodiment, the buttoms of the side walls of the body member define ledges on opposite sides of the V-shaped bottom wall. In another embodiment, the body member defines two grooves on opposite sides of the V-shaped bottom wall. A roller is mounted on the body member for movement longitudinally of the body member. The roller has a generally V-shaped circumference having an apex angle centrally located on the roller having a value of about 60° to 180°. The roller also has circumferentially extending grooves extending around both opposite sides of the outer periphery of the roller. With the clamping device, the lumen or orifice formed in the tubing is generally V-shaped, and the sides of the tubing are clamped to provide a relatively uniform flow rate and to minimize the effects of abusive tugs on the clamped tubing.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of application Ser. No. 102,112, filedDec. 10, 1979, now U.S. Pat. No. 4,340,201, which is acontinuation-in-part of application Ser. No. 893,263, filed Apr. 5,1978, now abandoned. This application also is a continuation-in-part ofapplication Ser. No. 283,807, filed July 16, 1981, now abandoned, whichis a continuation application of Ser. No. 101,800 filed Dec. 10, 1979,now abandoned, which is a continuation-in-part of Application Ser. No.893,263.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a clamping device for regulating fluid flowthrough flexible tubing and, more particularly, to a clamping device foruse in intravenous parenteral fluid administration sets.

2. Description of the Prior Art

Many clamps have been developed for controlling the rate of flow ofparenteral fluid administered to a patient through the plastic tubingwhich is used for transporting parenteral fluid from the solutioncontainer to the patient. However, these clamps have not proved asreliable and accurate in use as desired, particularly with respect toregulating and maintaining uniform flow rates.

Most clamps are designed to flatten tubing so that the walls of thetubing are more or less parallel producing a long flat oval-shapedlumen. The rate of flow of fluid through tubing compressed in thismanner is difficult to control precisely. Moreover, there isconsiderable strain imposed on the plastic by clamps of this type. Undersuch strain, most plastics undergo "cold flow" to relieve the straincausing the tubing to flatten still further and collapse inwardly thusdecreasing the fluid flow rates. As a result, the nurse or attendantmust frequently readjust the clamp to maintain relatively constant fluidflow.

A few clamps have been developed which do not flatten the tube uniformlyas shown, for example, in U.S. Pat. No. 3,685,787. This clamp consistsof a base having a tapered V-shaped groove into which plastic tubing isprogressively compressed by a roller in such a manner that there isessentially no space for the plastic to "cold flow" into since theperipheral surfaces of the tubing are confined.

Another attempt to solve the problem of controlling fluid flow inintravenous tubing is described in U.S. Pat. No. 3,802,463. With thisdevice, opposed walls of the tubing are variably compressed to modifythe size of a pair of lumens formed along the outer edges of thecompressed tubing. Central portions of the opposite walls are broughttogether in gradually increasing interior surface contact so that thelumens in the uncompressed outer edges gradually decrease in size untilflow of fluid through the tubing ceases.

Another problem associated with most clamps is the so-called "abusivetug" problem. The tubing used in intravenous sets for administeringparenteral solutions is typically made of soft polyvinyl chloride. Whenthe tubing is intentionally or accidentally given a strong tug, thetubing stretches. When the abusive tug is released, a large increase inflow rate occurs. An example of a clamp designed to avoid the effects ofan abusive tug is U.S. Pat. No. 4,047,694. In this clamp, the sideportions of the tubing wall are permitted to migrate into recessesformed between undercut shoulder portions of the roller or wheel and thesides of the clamp housing.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide aclamping device for regulating fluid flow through flexible tubing,particularly soft polyvinyl chloride tubing, which results in arelatively constant flow rate with time and minimizes the increase inflow rate which normally occurs after release of an abusive tug.

In accordance with the present invention, an improved clamping devicefor controlling fluid flow, such as intravenous fluid flow, is provided.The improved clamping device includes a roller and an elongated bodymember. The body member is formed of longitudinally extending parallelside walls and a bottom wall. Each of the side walls, in an upperregion, is provided with a longitudinally extending slot or groove forsupporting axially extending trunnions of the roller. The body member atits proximal end is enlarged to allow positioning of the roller withinthe body member with the trunnions of the roller guided in the slots orgrooves of the side walls. The bottom wall has a generally V-shape withthe apex of the V-shaped bottom wall positioned below the side walls.The apex angle of the V-shaped bottom wall is about 60° to 165°.

In one embodiment of applicant's invention, the distal or divergent endsof the V-shaped bottom wall merge with the bottoms of the side walls.

In another embodiment of applicant's invention, the bottoms of the sidewalls of the body member define body ledges. The body ledges have asubstantially constant width and height and extend from the proximal tothe distal end of the clamping device. Each of the body ledges isdefined by a ledge surface which is substantially parallel to the distalor divergent ends of the V-shaped bottom wall, and a ledge surface whichis substantially perpendicular to the axis of rotation of the roller.

In still another embodiment of applicant's invention, the body memberdefines two body grooves on opposite sides of the V-shaped bottom wall.The body grooves have a substantially constant width and depth andextend longitudinally from the proximal to the distal end of theclamping device. Each of the body grooves defines a body surface whichis substantially parallel to the distal or divergent ends of theV-shaped bottom wall, and a body surface which is substantiallyperpendicular to the axis of rotation of the roller.

The outer circumference of the roller also has a generally V-shapehaving its apex positioned centrally of the roller and its distal ordivergent ends extending toward the axis of rotation of the roller. Theapex angle of the roller is selected based on the angle of the apex ofthe bottom wall and is about 60° to 180°. Preferably, the apex angle ofthe roller is 10° to 50° more than the apex angle of the V-shaped bottomwall. The roller also has circumferentially extending roller groovesextending around both opposite sides of an outer circumferential portionor the outer periphery of the roller.

In one embodiment of the roller, the grooves have a substantiallyconstant width and depth. Each of such roller grooves defines a rollersurface which is substantially parallel to the axis of rotation of theroller, and a roller surface which is substantially perpendicular to theaxis of rotation of the roller. These surfaces cooperate with side wallsof the body member to clamp sides of the tubing so that substantiallyall fluid flow is through a central portion of the tubing.

In another embodiment of the roller, generally V-shaped grooves areformed on opposite sides of the outer peripheral portion of the roller.The apices of the grooves are inwardly spaced from the side edges of theouter peripheral portion. As a result, the width of the roller decreasesin a direction extending from the outer circumference or peripheralportion of the roller towards the axis of rotation of the roller. Theportions of the roller defining or forming the grooves cooperate withside walls of the body member to clamp sides of the tubing. The clampingforces on the tubing sides are greatest in the vicinity of the sideedges of the outer peripheral portion and decrease towards the axis ofrotation of the roller. Preferably, the clamping forces are such thatsubstantially all of the fluid flows through a lumen formed in a centralportion of the tubing.

The apex angle of the bottom wall, the apex angle of the roller, and theposition or orientation of the supports for the roller provided by theside walls of the body member are interrelated in such manner thatlongitudinal movement of the roller toward the distal end of the bodymember progressively compresses flexible tubing positioned between thebody member and the roller.

In one embodiment of applicant's invention, the apex angle of the bottomwall is constant while the distance between the supports for the rollerand the bottom wall progressively decreases in a direction toward thedistal end of the body member. Thus, as the roller moves toward thedistal end, the apex of the circumference of the roller progressivelymoves toward the apex of the bottom wall. In this manner, the lumen orfluid flow passage within the flexible tubing can be progressivelyreduced until a desired flow rate is obtained or until the tubing issufficiently compressed to prevent fluid flow.

In another embodiment of applicant's invention, the distance between thesupports for the roller and the distal or divergent ends of the V of theV-shaped bottom wall is constant while the apex angle of the bottom wallis progressively changed from a value less than the apex angle of theroller to a value approximately equal to the apex angle of the roller.This progressive change in apex angle is obtained by moving the apex ofthe bottom wall in an upward direction toward the roller, the width ofthe V-shaped bottom wall remaining constant.

In still another embodiment of applicant's invention, both the distancebetween the supports for the roller and the bottom wall and the size ofthe apex angle of the bottom wall are progressively changed. Thus, thisembodiment of applicant's invention combines the features of the twopreviously discussed embodiments.

With applicant's invention, the lumen or orifice formed in the tubing isgenerally V-shaped. Thus, compressive forces in the area of the lumen ororifice tend to be generally distributed across this portion of thetubing. This distribution of compressive forces tends to eliminate "coldflow" in the compressed tubing. In addition, since the tubing in thearea of the lumen or orifice is clamped in a V-shape, any inwardmovement of the upper and lower surfaces of the tubing is resisted.Thus, use of the device provides relatively uniform fluid flow throughthe tubing over extended periods of time. In addition, the size of thelumen or orifice experiences relatively less change during an abusivetug and recovers its size and shape more quickly after the abusive tugis released.

The invention, and its objects and advantages, will become more apparentin the detailed description of the preferred embodiments presentedbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description of the preferred embodiments of theinvention presented below, reference is made to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of one embodiment of a clamping device inaccordance with the present invention;

FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 taken alongline 2--2 of FIG. 1;

FIG. 3 is a cross-sectional view of the embodiment of FIG. 1 taken alongline 3--3 in FIG. 2;

FIG. 4 is a cross-sectional view of the embodiment of FIG. 1 taken alongline 4--4 in FIG. 2;

FIG. 5 is a cross-sectional view of the embodiment of FIG. 1 taken alongline 5--5 of FIG. 2;

FIG. 5A is an exploded view of the clamping area portion of FIG. 5;

FIG. 6 is a cross-sectional view of the embodiment of FIG. 1 taken alongline 6--6 of FIG. 2;

FIG. 7 is a view similar to FIG. 5A of another embodiment of theclamping device of the present invention;

FIG. 8 is a view similar to FIGS. 5A and 7 of still another embodimentof the clamping device of the present invention;

FIG. 9 is a view similar to FIG. 2 of another embodiment of the clampingdevice of the present invention;

FIG. 10 is a cross-sectional view of the embodiment of FIG. 9 takenalong line 10--10 of FIG. 9;

FIG. 11 is a cross-sectional view of the embodiment of FIG. 9 takenalong line 11--11 of FIG. 9;

FIG. 12 is a cross-sectional view of the embodiment of FIG. 9 takenalong line 12--12 of FIG. 9;

FIG. 13 is a view similar to FIG. 5A of another embodiment of thepresent invention; and

FIG. 14 is a view similar to FIG. 5A of still another embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Because clamping devices are well known, the present description will bedirected in particular to elements forming part of, or cooperating moredirectly with, the present invention. Elements not specifically shown ordescribed herein are understood to be selectable from those known in theart.

Referring now to the drawings, and to FIGS. 1-6 in particular, oneembodiment of the present invention is illustrated and will be describedin connection with a clamping device, generally designated 20.

The clamping device 20 has a body member 22 and a roller 24 operativelyassociated therewith. The body member 22 and the roller 24 arepreferably made of relatively rigid plastic or similar material. Thebody member 22 is generally elongated and has substantially parallelside walls 26, 28 and a bottom wall or floor 30. One or more members orstruts 31 interconnect ends of upper portions of walls 26 and 28.

The side walls 26, 28 have grooves or slots 32, 34, respectively, forsupporting trunnions 36 which extend axially from the roller 24 todefine an axis of rotation extending transversely of the body member 22.As illustrated in FIG. 2, both the proximal end 38 of the body member 22and slots 32, 34 are enlarged to define an opening 40 which facilitatesinsertion of roller 24 into the body member. Further, the flared ends ofthe side walls 26, 28 of the embodiment illustrated in FIG. 2 areaxially extended to define a space in which roller 24 can rest withoutapplying pressure to compressible, elongated flexible tubing 42positioned between the roller 24 and body 22. This feature ofapplicant's invention greatly facilitates movement of clamping device 20along tubing 42.

As illustrated in FIGS. 4, 5, 5A and 6, both a supporting portion ofbottom wall 30 and the circumference of roller 24 have a generallyV-shape. As seen in FIGS. 2 and 3, the supporting portion of bottom wall30 starts in the vicinity of line 4--4. Also, the roller 24 ispositioned in the slots 32, 34 in such manner that the apex 44 of bodymember 22 and the apex 50 of the roller 24 are in general alignment.Thus, the apices form cooperating clamping members that determine thesize of a lumen 56 formed in a central region of tubing 42.

The apex angle of the support or bottom wall 30 can vary from about 60°to 165°, and the apex angle of the wheel or roller 24 can vary fromabout 60° to 180°. Preferably, the apex angle of the bottom wall isabout 105° to 155°, more preferably about 120° to 135°. Also, the apexangle of the roller is preferably about 120° to 170°, more preferablyabout 150° to 165°. Further, the apex angles of the two members can beeither the same or different from each other. Preferably, the apex angleof the wheel or roller should be larger than the apex angle of thesupport or bottom wall. Normally, it is preferred that the apex angle ofthe wheel or roller be about 10° to 50° greater than the apex angle ofthe support, with about 15° to 30° being more preferred.

As illustrated particularly in FIGS. 2, 3 and 5A, the bottoms of theside walls 26, 28 form body ledges 60. The body ledges have asubstantially constant width and height and extend longitudinally fromthe proximal to the distal end of the clamping device. Each of the bodyledges 60 is defined by a ledge surface 62 which is substantiallyparallel to the distal or divergent ends and to the apex 44 of bottomwall 30, and a body surface 64 which is substantially perpendicular tothe axis of trunnions 36 and substantially parallel to side walls 26,28. The roller 24 has circumferentially extending roller grooves 68extending around both opposite sides of the outer periphery of theroller. Each of roller grooves 68 defines a roller surface 70 which issubstantially parallel to the axis of trunnions 36 or, in other words,the axis of rotation of roller 24, and a roller surface 72 which issubstantially perpendicular to the axis of trunnions 36.

Referring now particularly to FIG. 5A, each of roller grooves 68 has awidth "a" which is less than about 2 times the uncompressed nominal wallthickness of tubing 42. Preferably, the width "a" is about 1.6 to 1.8times the uncompressed nominal wall thickness of tubing 42. With thisarrangement, the sides of tubing 42 are under some compression so thatno flow lumen is present in the vicinity of roller grooves 68 when thetubing is clamped. This compression is along a line which issubstantially parallel to the axis of trunnions 36.

The distance between roller surfaces 70 and ledge surfaces 62 varies inthe embodiment illustrated in FIGS. 1-6 depending upon the position ofroller 24 relative to the distal end of body member 22. This distance ispreferably more than about 2 times the uncompressed nominal wallthickness of tubing 42 when the tubing is being clamped to providenormal flow rates, generally about 80 to 150 ml/hr and, more typically,about 100 to 125 ml/hr. This distance is selected in order to avoid anysignificant compression of the sides of tubing 42 between rollersurfaces 70 and ledge surfaces 62. In other words, this distance isselected to avoid any significant compression of the sides of tubing 42in a direction which is substantially perpendicular to the axis oftrunnions 36.

The most significant compression of the tubing 42 occurs between rollersurfaces 72 and ledge surfaces 64. This compression is achieved bycontrolling the size of the openings between roller surfaces 72 andledge surfaces 64. More specifically, the width "a" of roller grooves 68less the width "b" of body ledges 60 should be about 0.9 to 1.3 times,preferably about 1 to 1.2 times, the uncompressed nominal wall thicknessof tubing 42. In order to provide adequate compression in this area, aslight overlap "e" is preferably provided at normal flow rates betweenthe plane of ledge surfaces 62 and a line parallel to the axis oftrunnions 36 drawn through the distal ends of roller surfaces 72. Thisoverlap is preferably between about 0 to 0.5 times, preferably about0.25 times, the uncompressed nominal wall thickness of tubing 42. Also,it is generally preferred that the distance "f" between the distal ordivergent ends of the V of V-shaped roller 24 and the adjacent V-shapedbottom wall 30 at normal flow rates is about 1.2 to 1.8 times theuncompressed nominal wall thickness of tubing 42. This distance ismeasured along a line substantially perpendicular to the V-shaped bottomwall 30.

In order to provide the compressions discussed above in the variousareas of the tubing 42, it is preferred that the height "d" of ledges 60is about 1 to 2 times, preferably about 1.5 times, the uncompressednominal wall thickness of tubing 42. Also, the depth "c" of rollergrooves 68 is preferably greater than the height "d" of ledges 60 byabout 0.75 to 1.25 times the uncompressed nominal wall thickness oftubing 42. In addition, it is generally preferred that the periphery ofthe clamping area at normal flow rates be greater than the circumferenceof the uncompressed tubing 42. The "periphery of the clamping area" isdefined to mean the actual periphery around the cross-sectional areadefined between body 22 and roller 24 at normal flow rates such asillustrated in FIGS. 5 and 5A.

In operation, tubing 42 is placed inside body member 22 of clampingdevice 20 and the body member is moved to a desired position on thetubing. Roller 24 is then inserted into the opening 40 and trunnions 36are positioned in slots 32 and 34. The trunnions and slots are sodesigned that the trunnions fit in a loose manner within the slots. Thegradual slope of the slots 32, 34 provides the ability to constantlycontrol or vary fluid flow rates.

As the roller 24 moves to the left in FIG. 2, apex 50 progressivelypinches tubing 42 thus reducing the size of lumen 56 inside tubing 42.Thus, movement of roller 24 provides selective control of fluid flowthrough tubing 42. It should be noted that the manner in which apex 50compresses the walls of tubing 42 forms a V-shaped lumen 56, asillustrated in FIGS. 5 and 5A, which tends to evenly distribute thecompressive force exerted on tubing 42, thereby reducing the tendency of"cold flow" in the compressed tubing. Moreover, the lumen 56 does nothave a tendency to change in size or shape since any movement of theupper or lower wall is balanced by an equal movement of the other wall.In addition, because of the relatively high compressive force exerted ontubing 42 between ledge surfaces 64 and roller surfaces 72, the size offlow lumen 56 undergoes less change during an abusive tug and recoversits size and shape more quickly after the abusive tug is released.

To better illustrate this embodiment of applicant's invention, thedimensions of a preferred clamping device will be described. Thesedimensions are based on a tubing 42 having an outer diameter of about0.138 inch, an inner diameter of about 0.100 inch and a nominal wallthickness of about 0.019 inch. The width "a" of roller grooves 68 isabout 0.034 inch, the width "b" of body ledges 60 is about 0.012 inch,the depth "c" of roller grooves 68 is about 0.040 inch, the height "d"of body ledges 60 is about 0.027 inch, the overlap "e" is about0.004-0.005 inch at normal flow rates, the distance "f" is about 0.032inch at normal flow rates, and the width "g" of roller 24 is about 0.168inch. With these dimensions, the preferred apex angle of roller 24 isabout 165°, and the preferred apex angle of bottom wall 30 is about135°.

Turning now to FIG. 7, an embodiment of applicant's invention isillustrated which is essentially the same as the embodiment illustratedin FIGS. 1-6 with the exception of the grooves in the roller. With thisembodiment, reference numerals with primes attached have been used toidentify components similar to components illustrated in FIGS. 1-6.

As illustrated in FIG. 7, roller grooves 68' are formed in roller 24' todefine roller ledges 76 at the distal or divergent ends of the V ofV-shaped roller 24'. Each of ledges 76 defines a surface 78 which issubstantially parallel to the axis of trunnions 36 and a surface 80which is substantially perpendicular to the axis of trunnions 36.Surfaces 80 of roller ledges 76 face surfaces 64' of body ledges 60'. Inthis embodiment, the width b₁ ' of each of body ledges 60' is reduced sothat the combined width b₁ ' of body ledges 60' and the width b₂ ' ofroller ledges 76 (b₁ '+b₂ ') in FIG. 7 is approximately equal to thewidth "b" of each of body ledges 60 in FIG. 5A. Dimensions a', c', d',e', f' and g' are substantially the same as the corresponding dimensionsin FIG. 5A. The clamping device in FIG. 7 operates in essentially thesame manner as the embodiment illustrated in FIGS. 1-6 and producesessentially the same compressive forces as discussed with respect toFIG. 5A.

Referring now to FIG. 8, an embodiment of applicant's invention isillustrated in which grooves are formed both in the roller and the bodyto minimize the effects of an abusive tug. With this embodiment,reference numerals will be combined with alphabetical characters toidentify features similar to those previously described with referenceto FIGS. 1-6.

In FIG. 8, body member 22a defines two body grooves 84 on opposite sidesof V-shaped bottom wall 30a. The body grooves 84 are of constant depthand width and extend longitudinally from the proximal to the distal endof the clamping device. Each of body grooves 84 defines a body surface86 which is substantially parallel to the distal or divergent ends andto the apex 44a of bottom wall 30a, and a body surface 88 which issubstantially perpendicular to the axis of trunnions 36. In thisembodiment, the width A of roller grooves 68a is less than about 2 timesthe uncompressed nominal wall thickness of tubing 42a to providecompression of tubing 42a in the vicinity of roller grooves 68a when thetubing is clamped. This compression is in a direction substantiallyparallel to the axis of trunnions 36. Preferably, the width A is about1.2 to 1.5 times the uncompressed nominal wall thickness of the tubing42a. The width H of body grooves 84, as illustrated in FIG. 8, isslightly greater than the width A of roller grooves 68a. This width Halso is less than about 2 times the uncompressed nominal wall thicknessof tubing 42a and can be the same or different from the width A. Thedepth C of roller grooves 68a and the depth I of body grooves 84 areapproximately the same and are preferably approximately equal to theuncompressed nominal wall thickness of tubing 42a. The spacing J betweenthe distal or divergent ends of the V of V-shaped roller 24a and thedistal or divergent ends of the V of V-shaped bottom wall 30a is about1.6 to 2.2 times, preferably about 1.8 times, the uncompressed nominalwall thickness of tubing 42a at normal flow rates.

The operation of the clamping device of FIG. 8 is essentially the sameas that previously described with reference to FIGS. 1-6. Also insimilar manner to the embodiment illustrated in FIGS. 1-6, thecompression of the tubing at both sides in a direction substantiallyparallel to the axis of the roller trunnions (not shown) acts tominimize the increase in flow rate which normally occurs after releaseof an abusive tug. Also, as with respect to the embodiment illustratedin FIGS. 1-6, no flow lumen is formed at the sides of the tubing 42awhen the tubing is clamped.

To better illustrate this embodiment of applicant's invention, thedimensions of a preferred clamping device will be described. Thesedimensions are based on a tubing having the same dimensions discussedwith respect to FIGS. 1-6. The width A of roller grooves 68a is about0.025 inch, the depth C of roller grooves 68a is about 0.020 inch, thewidth G of roller 24a is about 0.144 inch, the width H of body grooves84 is about 0.029 inch, the depth I of body grooves is about 0.021 inchand the spacing J is about 0.038 inch at normal flow rates. With thesedimensions, the preferred apex angle of roller 24a is about 150° and thepreferred apex angle of bottom wall 30a is about 125°.

Turning now to FIGS. 9-12, an embodiment of applicant's invention isillustrated which is similar to the embodiment illustrated in FIG. 8except that the clamping area for regulating the flow rate is controlledby increasing the apex angle of the support or body wall from theproximal to the distal end of the clamping device. With this embodiment,corresponding reference numerals in the "100" series have been used toidentify components similar to components previously described.

As illustrated in FIGS. 9-12, clamping device 120 has a body 122 formedof substantially parallel side walls 126, 128 and a bottom wall or floor130. The bottom wall 130 has a generally V-shape with the apex of the Vpreferably centered between and located below the bottom of the sidewalls. The side walls 126, 128 include slots or grooves 132, 134 forsupporting trunnions 136 of roller 124. As illustrated in FIG. 9, theslots have an enlarged opening 140 and extend longitudinally toward thedistal end of body 122. For most of their length, the slots aresubstantially parallel to the bottom edge of side walls 126, 128.

With this embodiment, compression of the tubing 142 for regulating theflow rate is obtained by gradually changing the apex angle of the bottomwall 130. For instance, as illustrated in FIG. 11, the roller 124 has anapex angle of approximately 150° while the bottom wall 130 has an apexangle of approximately 100°. The apex angle of the bottom wall isgradually changed by moving the apex in an upward direction toward theroller until the apex angle of the bottom wall reaches a desired value,such as approximately 150°, as illustrated in FIG. 12. The distanceseparating the distal or divergent ends of the V-shaped bottom wall 130or, in other words, the width of the V-shaped bottom wall adjacent bodygrooves 184, remains unchanged during the upward movement of the apex144 of bottom wall 130 toward the roller. The embodiment illustrated inFIGS. 9-12 functions in basically the same manner as the embodimentdescribed in FIG. 8 except that the distance J remains constant.

Considering now FIG. 13, still another embodiment of applicant'sinvention is illustrated. This embodiment is similar to the embodimentsillustrated in FIGS. 1 to 8, with the primary difference being the shapeof the roller grooves. In the following description, correspondingreference numerals in the "300" series will be used to identifycomponents similar to those previously described.

FIG. 13 illustrates a portion of a clamping device 320 having a bodymember 322 and a roller 324. The floor 330 of the body member 322 isformed from two planar surfaces having outer edges merging with thebottom edges of the side walls of the body member. Such floor has aV-shaped groove with an apex angle between 60° and 165° for receivingand supporting tubing being compressed. Preferably, the apex angle ofthe groove is between approximately 120° and 160°, with a value ofbetween approximately 130° and 145° being more preferred.

Preferably, the width and depth of the floor 330 are constant.Compression of the tubing is effected by shaping the side walls of thebody member 322 so that the trunnions (not illustrated) of the roller324 are moved towards the floor 330 as the roller moves from theproximal towards the distal end of the body member. For instance, thesupports for the trunnions are shaped to provide a slope of about onedegree.

The roller 324 has a central portion 324a carrying the trunnions thathas a substantially constant width. An outer peripheral portion 324b ofthe roller has a width less than that of the central portion and isshaped to cooperate with the floor 330 to clamp a central portion of thetubing so as to define a flow lumen within the tubing. Circumferentiallyextending roller grooves 368 extend around both sides of the outerperipheral portion 324b of the roller. The grooves are generallyV-shaped and have apices inwardly spaced from side edges of the outerperipheral portion. Each of the roller grooves 368 defines a firstroller surface 372 extending inwardly toward the center of the rollerand a second roller surface 370 interconnecting an inner end of theroller surface 372 with an outer edge of the central portion 324a. Thesurfaces 372 are tapered inwardly so that the width of the rollerprogressively decreases in a direction extending inwardly from the outerperipheral portion 324b of the roller.

As with the embodiment illustrated in FIG. 13, the outer peripheralportion 324b of the roller is substantially flat. The roller 324 has aknurled surface to enhance frictional engagement between the roller andthe tubing and to facilitate movement of the roller by a user of theclamping device.

In one embodiment of the clamping device illustrated in FIG. 13 that isused to compress tubing having the previously described dimensions, theroller surfaces 372 are planar surfaces extending inwardly from outersides of the peripheral surface 324b. Extensions of such surfaces formacute angles with the axis of the roller trunnions. Such angles arepreferably between 65° and 75°, with values between approximately 69.5°and 70° being especially preferred. The distance between the innersurfaces of the side walls of the body member 322 is preferably between0.165 and 0.170 inches. The width of the peripheral portion 324b ispreferably between approximately 0.104 and 0.122 inches. The width ofthe peripheral portion 324b and the amount of inward taper of thesurface 372 are selected such that no flow lumens are formed in sideportions of the tubing. Preferably, the distance between the side oredge of the peripheral portion 324b and the adjacent side surface of thebody member 322 is between approximately 1 and 1.7 times the nominalwall thickness of the uncompressed tubing. Preferably, the distancebetween the outer edge of the peripheral portion 324b and the surface370 is between 0.030 and 0.045 inches. It is preferable that suchvertical distance be such that outer ends of the tubing side portionsjust contact the surfaces 370 during regulation of normal flow rates sothat minimal compressive forces acting in directions perpendicular tothe axis of the trunnions are exerted on portions of the tubing receivedin the spaces defined between the grooves 368 and the body member sidewalls.

Considering now FIG. 14, another embodiment of applicant's invention isillustrated. This embodiment is similar to the embodiment illustrated inFIG. 13 and reference numerals in the "400" series will be used toidentify components similar to components previously described.

FIG. 14 illustrates a clamping device 420 having a roller 424 movablewith respect to a body member 422. The body member 422 has a V-shapedbottom wall or floor 430 shaped in a manner similar to the floor 30 ofthe embodiment illustrated in FIG. 5A. The outer peripheral portion 424bof the roller is shaped similar to the outer peripheral portion of theroller 24 in FIG. 5A. Also, the roller 424 has roller grooves 468similar to the roller grooves 368 used with the embodiment illustratedin FIG. 13. As with the embodiment of FIG. 13, the maximum distancebetween the roller surface 472 and the side wall of the body member 422is such that no flow lumens are formed in side portions of the tubing.The distance between the edge of the peripheral portion 424b and theledge surface 464 is preferably approximately equal to the uncompressednominal thickness of one wall of the tubing.

The embodiments illustrated in FIGS. 13 and 14 are designed to minimizethe adverse effects of abusive tugs on compressed tubing. The rollergrooves are cut so that the sides of the tubing tend to bulge into thespaces formed between the grooves and side walls of the body member.When the tubing is subjected to an abusive tug, the inclined surfacestend to resist movement of the tubing so that the central region of thetubing maintains its desired configuration, and the flow rate is notchanged. Another advantage provided by the tapered side walls of theroller is the tendency of tubing to self center with respect to theroller body during translation of the roller.

While FIGS. 13 and 14 illustrate grooves having planar walls, othersurfaces are usable to define one or both of the groove walls. Whateverthe shape selected, it is preferable for the compressive forces actingon the sides of the tubing to be greatest in the region adjacent edgesof the roller outer peripheral portion. In this manner, any tendency ofthe tubing side walls to move inwardly when the tubing is subjected toan abusive tug is resisted. Also, the rollers illustrated in FIGS. 13and 14 can be combined with a body member of the type illustrated inFIG. 8.

As in the previously described embodiments, when the apex angle of theroller is 60° or slightly more, the point or apex of the V-shape of theroller is slightly rounded or curved to facilitate movement of theroller along the tubing. Also, the V-shaped portion of the roller can beslightly knurled or axially slotted or ridged, as generally indicated inFIG. 1, to facilitate turning of the roller. Further, this provides alimited degree of frictional resistance between the compressed tubingand the roller that tends to maintain the roller in a desired position.In addition, the side walls of the roller adjacent the side walls of thebody member can be serrated or formed with ridges to reduce thepossibility of slippage between the sides of the roller and the sidewalls of the body member.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention. For instance, the embodiments of applicant's inventionillustrated in FIGS. 1-8 and 13-14 can be combined with the embodimentillustrated in FIGS. 9-12 to form a device in which the slots forguiding the trunnions of the rollers are angled progressively downwardlyin a direction toward the distal end of the body and the apex angle ofthe bottom wall increases in a direction toward the distal end of thebody. In addition, the apex angle of the bottom wall in the embodimentsillustrated in FIGS. 1-8 and 13-14 can be abruptly increased at the fardistal end of the clamping device to equal the apex angle of the rollerrather than being progressively increased as in the embodimentillustrated in FIGS. 9-12. These and other modifications of thedisclosed devices will be readily apparent to those skilled in the artand are intended to be covered by the appended claims.

What is claimed is:
 1. An intravenous tubing clamping device forcontrolling fluid flow through compressible tubing comprising:anelongated body member adapted to receive said tubing having a proximalend and a distal end; said body member including a generally V-shapedbottom wall defining two planar supporting surfaces for said tubingextending longitudinally of said body member and having a substantiallyconstant width and an apex angle of about 60° to 165°; and a rollermounted on said body member for movement longitudinally of said bodymember about an axis of rotation extending transversely of said bodymember for defining a clamping area between said roller and saidsupporting surfaces which decreases the cross-sectional area of thelumen of the tubing as said roller moves from said proximal end of saidbody member toward said distal end, said roller defining groovesextending circumferentially around opposite sides of the outercircumference of said roller, said roller grooves defining spacesadapted to receive the sides of a tubing clamped in said clamping area,said roller grooves being defined by (1) side walls on said body memberextending substantially parallel to said longitudinal roller movement onopposite sides of said roller, (2) first surfaces formedcircumferentially on said roller adjacent to and on opposite sides ofsaid clamping area, and (3) second surfaces formed circumferentially onsaid roller substantially perpendicular to said body member walls andeach extending substantially parallel to said axis of rotation between arespective first surface and body member wall, said roller groovescooperating with said body member to clamp the sides of said tubing in adirection transverse of said body member with said tubing beingcompressively engaged between said body member walls and said firstsurfaces, said first surfaces being inclined inwardly so as to formacute angles with said second surfaces thereby reducing the width ofsaid roller in a region spaced inwardly from the outer circumference ofthe roller, the outer peripheral portion of said roller having distalends merging with the portions of said roller defining said grooves, andsaid tubing being positively engaged by said second surfaces so that alumen is defined in a central portion of the tubing through which flowssubstantially all of the fluid, said roller having a circumference witha generally V-shape with the apex of the V-shape centrally located onthe roller and its distal ends merging with said roller grooves, theapex having an angle of about 60° to 180°, the roller cooperating withthe planar supporting surfaces of said body member to define a generallyV-shaped lumen in the clamped tubing.
 2. An intravenous tubing clampingdevice according to claim 1, wherein said tubing is positively engagedby said second surfaces during movement of said roller towards thedistal end of said body member.
 3. An intravenous tubing clamping deviceas claimed in claim 1, wherein the apex angle of the bottom wall of thebody member is progressively changed from a value less than the apexangle of the roller to a value approximately equal to the apex angle ofthe roller by moving the apex of the bottom wall in an upward direction.4. An intravenous tubing clamping device as claimed in claim 1, whereinthe apex angle of the roller is at least 10° more than the apex angle ofthe bottom wall.
 5. An intravenous tubing clamping device as claimed inclaim 1, wherein said roller has planar roller surfaces cooperating withsaid planar supporting surfaces of said body member to form a V-shapedlumen in a central portion of clamped tubing.
 6. An intravenous tubingclamping device as claimed in claim 1, wherein the distance between thedistal ends of said generally V-shaped bottom wall and the outercircumference of said roller adjacent said roller grooves measured alonga line substantially perpendicular to said axis of rotation of saidroller is about 1.6 to 2.2 times the uncompressed nominal wall thicknessof said tubing when said tubing is clamped.
 7. An intravenous tubingclamping device as claimed in claim 6, wherein said distance is about1.8 times the uncompressed nominal wall thickness of said tubing.
 8. Anintravenous tubing clamping device as claimed in claim 1, wherein saidroller has axially extending trunnions, and wherein said body memberincludes means for supporting said trunnions for movement toward thebottom wall as said roller moves from said proximal end of said bodymember toward said distal end.
 9. An intravenous tubing clamping deviceas claimed in claim 1, wherein said device further comprises guide meanson said body member for guiding longitudinal movement of said roller,the distance from the guide means to the bottom wall progressivelydecreasing toward the distal end of the body member.
 10. An intravenoustubing clamping device as claimed in claim 9, wherein the apex angle ofthe V-shaped groove in the bottom wall increases over at least a portionof the length of the V-shaped groove in a direction from the proximal tothe distal end of the body member.
 11. An intravenous tubing clampingdevice as claimed in claim 1, wherein the apex angle of the V-shapedgroove in the bottom wall increases over at least a portion of thelength of the V-shaped groove in a direction from the proximal to thedistal end of the body member.
 12. An intravenous tubing clamping devicefor controlling fluid flow through compressible tubing comprising:anelongated body member adapted to receive said tubing having a proximalend and a distal end; said body member including a generally V-shapedbottom wall defining two planar supporting surfaces for said tubingextending longitudinally of said body member and having a substantiallyconstant width and an apex angle of about 60° to 165°, said body memberfurther including grooves extending longitudinally on opposite sides ofsaid V-shaped bottom wall, outer edges of said planar supportingsurfaces defining top edges of said body member grooves, said bodymember grooves defining spaces adapted to receive a portion of the sidesof a clamped tubing; and a roller mounted on said body member formovement longitudinally of said body member about an axis of rotationextending transversely of said body member for defining a clamping areabetween said roller and said planar supporting surfaces which decreasesthe cross-sectional area of a lumen formed in a central region of theclamped tubing as said roller moves from said proximal end of said bodymember toward said distal end, said roller defining grooves extendingcircumferentially around opposite sides of the outer circumference ofsaid roller, said roller grooves defining spaces adapted to receive aportion of the sides of a tubing clamped in said clamping area, saidroller grooves being shaped so that the clamping forces on the sides ofthe tubing are greatest in the vicinity of the edges of the outerperipheral portion of said roller and decrease in a direction extendingtowards the axis of rotation.
 13. An intravenous tubing clamping deviceas claimed in claim 12, wherein the depth of said roller grooves andsaid body member grooves is approximately equal to the uncompressednominal wall thickness of said tubing.
 14. An intravenous tubingclamping device as claimed in claim 12, wherein said body member groovesand said roller grooves clamp sides of the tubing so that no flow lumensare formed at sides of the tubing.
 15. An intravenous tubing clampingdevice as claimed in claim 12, wherein the width of said roller groovesand said body member grooves is less than about 2 times the uncompressednominal wall thickness of said tubing.
 16. An intravenous tubingclamping device as claimed in claim 12, wherein said width of saidroller grooves and said body member grooves is about 1.2 to 1.5 timesthe uncompressed nominal wall thickness of said tubing.
 17. Anintravenous tubing clamping device as claimed in claim 12, wherein thewidth of said body member grooves is greater than the width of saidroller grooves.
 18. An intravenous tubing clamping device as claimed inclaim 12, wherein the depth of said body member grooves and the depth ofsaid roller grooves are approximately the same.
 19. An intravenoustubing clamping device as claimed in claim 12, wherein said body membergrooves and said roller grooves compress both sides of the tubing in adirection substantially parallel to an axis of the roller to therebyminimize a change in flow rate when the tubing is subjected to anabusive tug.
 20. An intravenous tubing clamping device as claimed inclaim 12, wherein the widths of said body member grooves and said rollergrooves are less than twice the width of uncompressed tubing so thatsides of said tubing are clamped in a direction transverse of said bodymember to thereby oppose movement of the tubing when the tubing issubjected to an abusive tug.
 21. An intravenous tubing clamping deviceas claimed in claim 12, wherein said roller grooves are defined by firstsurfaces extending inwardly from opposite sides of the outer peripheralportion of the roller and second surfaces extending from inner edges ofsaid first surfaces towards side walls of said body member, said rollerhaving a central portion with outer edges merging with outer edges ofsaid second surfaces, extensions of said first surfaces forming acuteangles with the axis of rotation.
 22. An intravenous tubing clampingdevice according to claim 21, wherein said second surfaces extendgenerally parallel to the axis of rotation.
 23. An intravenous tubingclamping device according to claim 12, wherein the width of said rolleris decreased by the grooves so that the distance between sides of theroller and side walls of said body member increases in a directionextending from the outer peripheral portion towards the axis of rotationof the roller, the roller having a central portion with a width greaterthan the width of the outer peripheral portion.